There's copyright infringement here, it's true, but it isn't the copyright violation Viacom's talking about, and nobody's going to make a YouTube re-enactment which outsells the original.

4. Funny Animals

Copyright infringement was the YouTube killer app for me, not too long ago. Then two things happened. First, Viacom got all the Daily Show clips taken down. For months I didn't go near YouTube. Second, the breakbeat producer Miyagi posted on a breakbeat discussion board that when he gets bored he googles YouTube for "funny animals." This just about changed my life.

5. Teenage Girls Dancing

I don't really understand this, but it's a whole subgenre. They usually can't dance, and they record the music with their webcams, so it sounds awful. I'm not saying it's a good use case, but it's certainly a popular one.

6. Music Videos & Just Music Itself

Like re-enactments, there is copyrightinfringementhere, so technically it supports Jeff's argument, but the music companies never pull videos. They know it sells. Like re-enactments, a music video on YouTube is more likely to advertize a piece of music than to replace it.

Long story short, Viacom, by valuing their lawsuit at $1 billion - close to YouTube's $1.65 billion purchase price for Google - is asserting that most of YouTube's value comes from their content. I think Viacom - and the entertainment industry in general - does have a very argument to obtaining some portion of Google's advertizing income from YouTube clips made out of their material, whether remixed or not, but probably not as much as they think.